Introduction: Interventional ASD closure is generally a safe procedure with only a small amount of severe side effects including mainly erosion of the atrial wall, embolizations and arrhythmias. The IRFACODE study has shown excellent results in Patients with various generations of the Occlutech devices. IRFACODE II study will evaluate the performance and safety of the Occlutech® Flex II device in patients with closure of secundum atrial septal defects (ASD II).